Improved construction of saw-teeth



UNITED STATES PATENT OFFICE.

VILLIAM A. WILSON, OF BERLIN FALLS, NEW HAMPSHIRE.

IMPROVED CONSTRUCTION OF SAW-TEETH.

Specification forming part of Letters Patent No. 23,330, dated March 22,1859.

T0 l/ZZ whom t may concern.-

Be it known that I, WILLIAM A. WILSON, of Berlin Falls, in the county ofCoos, in the State of New Hampshire, have invented certain new anduseful Improvements in the Construction of Saws, by adapting them to thepurpose of sawing and planing lumber of every description by one and thesame operation, constituting what I denominate the planing-saw; and I dohereby declare the following to be a full, clear, and exact descriptionthereof, reference being had to the annexed drawings, making part ofthis specification, in which- Figure l represents a side and Fig. 2 anedge view showing my improved form of teeth as applied to circular saws.Fig. 3 represents a side and Fig. 4 an edge view of a fragment of aplate, showing the adaptation of my improvement to reciprocating saws.

I am aware that attempts have been made to construct the teeth of sawsfor the purpose of sawing and planing boards simultaneously; butbyreason of defects both in the construction and arrangement of the teeththey have proved entire failures. After much experiinenting I havediscovered that the particular form and construction of teeth shown inthe drawings is best adapted to the purpose, especially in relation tothe facility with which they clear themselves in the kerf, and alsobecause such arrangement and construction of teeth do not impede theoperation of the saw-teeth, and as the sawing-teeth have no lateral setthey necessarily make less kerf than ordinary saws, thereby effecting asaving of timber.

In the drawings, A represents vthe sawing` teeth, having their frontcutting-edges made in the usual form. The back of each tooth, however,does not extend to the throat of the adjacent one, but terminates atabout onethirdlthe distance of its length from the point planer in one.The planing-teeth being thus located in the rear of the sawing-teeth,are for the purpose of planing at one and the same motion of the saw.Their points are chiselshaped, with their apices slightly rounded. Theobject of thus rounding the tips of the planers is for the purpose ofallowing the bevel to extend regularly back from its point; otherwise itwould be prevented from passing freely and easily through the material.These planes have a planing-surface sufficient to plane and smooth theportion cut by the preceeding saw-tooth. The planing-edge being set atabout right angles to the saw-tooth, the back of said planer terminatesin the throat of said saw-tooth. The angles at which the planing-edgesare set, it will be seen, also form a tangent to a circle abouttwo-thirds of the diameter of the saw and cause the said planing-edgesto act upon the grain of the material with a draw-knifestroke during theentire revolution of the saw. teeth are beveled alternately on oppositesides of the saw, and they also have a lateral set suited to theirbevel. Each planing-tooth extends to the circle formed by the saw-teethand is constructed with a throat c, which intersects the back of eachsaw-tooth and separates it therefrom, so as to form a space directlybeneath the'edge of the planing-point for the several purposes ofenabling the cutting and planing edges of the teeth to be set parallelto the face of the saw from the base to their apices, and to make thespace between the apex of the sawing-tooth and the planer sufficientlylarge to receive the shaving cut by the planing-tooth and let it passoft withoutchoking, and also to facilitate the filing of the saw-teeth.

The planing-teeth of Athis saw may also be set toward one side for thepurpose of planing or smoothing one or both sides of such boards ormaterial (by reversing the same) as have been. sawed in the ordinaryWay. It is obvious, too, that by this arrangement in sawing timber thematerial being sawed may be planed on one side only.

The teeth of the circular saw may be sharpened from time to time, asrequired,by a new method that I have discovered, and which consists inmounting a hard or turkey bone in a suitable adjusting device in suchaman- These planing- Combining the planing with the sawing tooth sothatthe Cutting-edge of theformer shall be in rear of and at about rightangles to the back of the latter, having the throat between, as setforth and shown hereinbefore.

In testimony whereof I hereunto subscribe my name.

WILLIAM A. WILSON.

Witnesses:

GEO. K. SHAW, MosEs KELLY.

